THE PROBLEM

Machining inherently involves the deformation of near-surface of a workpiece to remove material and achieve the required component geometry and finish. High levels of deformation are known to lead to the formation of defects such as white layers and distorted layers, which are known to significantly reduce fatigue life. Assessment of such surface integrity defects in currently requires destructive cross-sectional optical or scanning electron microscopy.

The limitations of the current approach (cross-sectional microscopy) significantly hamper the speed and sustainability of component verification:

1. Destructive: Sacrifices valuable parts resulting in waste.

2. Time-consuming: Long lead times (1 week - 1 month) hinder responsiveness.

3. Subjective: Operator-dependent interpretation of results leads to measurement variation.

4. Limited scope: Cannot inspect production parts directly or achieve large part coverage.

This lack of accurate, timely, and non-destructive surface integrity assessment hinders:

• Performance: Defects compromise component lifespan and functionality, leading to costly failures.

• Safety: Conformance cannot be checked for production components, so verification is limited to 1 in 100 parts.

• Sustainability: Destructive testing leads to material waste. The inability to verify production components means the product life-cycle can't be maximised. The cross-section method uses chemicals to etch the surface.

• Efficiency: The long time frame for inspection creates production and R&D bottlenecks and inefficiencies whilst reducing responsiveness and fixed manufacturing processes.

This critical gap in capability demands a transformative solution for surface integrity assessment in the aerospace industry.